Reply With Quotethe square heads are better heads, and the manifold would work good with that combo, or get a new dual plane manifold for the oval heads
I have a big block 454 in my carrera. When I purchased it used it had a gm square port intake on oval port heads. if these are good heads, should I just change the intake, or should I change the heads?
the square heads are better heads, and the manifold would work good with that combo, or get a new dual plane manifold for the oval heads
the square ports are better for higher rpm use .if you plan on staying below 5500 stay with the oval port they are better for torque.
Someone didn't know how to put an engine togeather. You can put an oval port intake with rec. port heads but not the other way around. If you don't plan on building the motor install the oval port intake. You should see an improvement in performance due to the fact that the gas is hitting a brick wall when it hits the heads. Have Jim Valakeo do the heads and intake and you will really notice the improvement.
Tinkerboater, on your reply about the oval port intake on square port heads. I run just the opposite, due to the fact that the holes in the square port intake are bigger than the oval port heads which creates a turbulence on the intake charge. But you must run square port gaskets. Read an article in Hot boat a few years back about a racer who used this setup in his dragboat. He did put larger exhaust valves in the heads to increase the exhaust flow. I have ran two different motors this way and they worked fine.
As I said you can run an oval port intake with rec. port heads. This will increase velocity in the ports. But you should never install a rec. port intake on oval port heads unless the heads are port matched to the intake. some turbulence is good to keep the fuel in suspension but what you get with out the port matching is blockage to the flow.
Posting Permissions